National 5 Course Flashcards
What is a chemical reaction
When two or more REACTANTS react with one another to produce one or more PRODUCTS
Why does a chemical reaction occur
As the particles of the two reactants collide with each other with enough energy to combine
What is the rate of a reaction
The time taken for the reactants to turn into products
What is the formula for rate of reaction
Rate = change in quantity/change in time
What are the four variables that control the rate of a reaction
+ temperature
+ concentration
+ presence of a catalyst
+ particle size
How does temperature affect the rate of a reaction?
Increasing the temperature of a reaction provides the particles with increased energy, in the form of heat, which they use as kinetic propellers. This results in the particles colliding more frequently and with an increased amount of energy.
Increase in temperature = increase in rate of reaction
How does concentration affect the rate of a reaction?
By increasing the concentration of a reaction, more particles exist in the same fixed volume - resulting in them colliding more frequently
Increase in concentration = increase in rate of reaction
What is a catalyst
A catalyst is a substance which increases the rate of a chemical reaction whilst remaining unchanged in the process.
How does particle size affect the rate of a reaction?
By decreasing the particles size, more particles are able to exist within the volume - resulting in them colliding more often.
Decrease in particle size = increase in rate of reaction
What are the two types of catalyst
+ HOMOgenous
+ HETEROgenous
What is a homogenous catalyst
A catalyst which is in the same state of matter as the reactants
What is a heterogenous catalyst
A catalyst which is in a different state of matter as the reactants
What occurs to the reactants and product concentration as the reaction occurs
Reactant concentration decreases
Product concentration increases
What are the three states of matter
+ solid
+ liquid
+ gas
What is the structure of a solid
Tightly bound particles in a regular arrangement with a fixed volume and shape
What is the structure of a liquid
Loosely bound particles with a fixed volume but no fixed shape.
What is the structure of a gas
Free moving particles without a fixed mass or volume
What is a mixture
Two or more elements mixed, but not joined, together.
What is a compound
Two or more elements chemically joined together
What is an element
A substance which contains only 1 type of atom
What is the measure of a substance’s ability to dissolve in a solvent
Solubility
What is the measure of a substance’s ability to mix with another substance
Miscibility
What is a saturated solution (this topic only)
One in which no more solute can dissolve
What is a group in the periodic table
A vertical column
What is a period in the periodic table
A horizontal row
What is the top-left number of an element in nuclide notation form
It’s mass number
What is the bottom-left number of an element in nuclide notation form
It’s atomic number
What is an element’s:
A: mass number
B: atomic number
A: It’s combined number of protons + neutrons
B: it’s number of protons
What is the name of the different levels of electron arrangement in an atom
Energy levels/ Valencia’s
What is a stable electron arrangement and what group in the periodic table naturally occur with this arrangement
A stable electron arrangement is when an atom has 8 electrons in its outer valency.
Group 8 (noble gases) have this arrangement
How do atoms attempt to achieve this stable arrangement
They either lose or gain electrons
What do atoms form when they lose/gain electrons and what is the name of this process
They form ions
Known as ionisation
What are isotopes
Elements which contain the same number of protons, however a different number of neutrons - meaning they have different mass numbers
What does -IDE mean on the end of a compound
There are two elements in the compound
What does -ATE mean on the end of a compound
There are three elements within the compound, one of which is oxygen
What are the two main types of bonding that atoms undergo
- covalent
- ionic
What is covalent bonding
When two non-metals share a pair of outer electrons ( the electrons are attracted to the positive nucleus and are therefore not repelled by the electrons)
What are diatomic elements
Elements which naturally exist as two atoms, covalently bonded.
What are the seven diatomic elements
- hydrogen
- oxygen
- nitrogen
- bromine
- iodine
- chlorine
- ## fluorine
What are the two types of covalent structures
+ covalent networks
+ covalent molecular
What is a covalent network
A 3 dimensional lattice of multiple covalently bonded atoms
What is a covalent molecule
Two or three atoms covalently bonded
Do… have high or low melting points and conduct electricity in any state?
A: covalent networks
B: covalent molecules
A: very high melting and boiling points
Doesn’t conduct electricity in any state
B: low melting and boiling points
Doesn’t conduct electricity in any state
What are ionic bonds
When a metal and a non-metal exchange at least 1 electron in an attempt to both gain a stable arrangement
Upon ionic bonding, what do the atoms become
Charged ions
What holds ionic bonds together
The electrostatic force of attraction between the positive and negative ions
What is the name of the structure of an ionic compound
An ionic lattice
Do ionic compounds have high or low melting points and do they conduct electricity?
They have high melting and boiling points
They conduct electricity when molten or in solution as the ions are free to move
What does the chemical formula of a compound show
The type of elements in the compound as well as the number of atoms of each element
What does the prefix... mean? A: mono B: di C: tri D: tetra E: penta F: hexa
A: 1 B: 2 C: 3 D: 4 E: 5 F: 6
When a metal loses electrons does it become a positive or negative ion
Positive
When a metal gains electrons does it become a positive or negative ion
Negative
How many atoms of oxygen are there nitrogen trioxide
3
How do you find the chemical formula of a compound
1: take the Valencies of both elements
2: swap them so that each element has the opposite valency
3: drop the new valencies to the bottom right corner of each element symbol
What must you include in ionic equations
The charge of the element
What must you include in state equations
The state of matter of all the involved elements
What is balanced equation
One that has an equal number if atoms of each element on both sides of the equation
Where do you place the numbers in an equation to balance it
In front of the element or compound
What is the equation used to find the Relative atomic mass of an element with multiple isotopes
(% x mass of isotope A) + (% x mass of isotope B)…/ 100
How do you find the relative formula mass of a singular compound
Add the combined masses of each element in the compound (remembering to take into account the number of each atom)
If given mass and gfm what is the equation to find the number of moles of a substance
N = m/gfm
If given concentration and volume what is the equation to find the number of moles in a substance
N = C x V
What is the pH of a substance
It’s concentration of hydrogen ions
What are the two types of substance - based on their pH
+ Acids
+ Alkalis
What pH do acids have
Less than 7 on the pH scale
What pH do alkali have
More than 7 on the pH scale
How does an alkali form
When a metal oxide dissolves in water (soluble base)
How does an acid form
When a non-metal oxide dissolves in water
How can you determine if a substance is an acid or alkali based on its concentration of hydrogen ions
Acids have a higher concentration of hydrogen ions than hydroxide ions
Alkalis have a higher concentration of hydroxide ions than hydrogen ions
What is the name of the reaction between an acid and an alkali, in which the pH rises/falls to 7
Neutralisation
What is the name of the reaction when water is added to an acid or alkali, resulting in the pH falling/rising to 7
Dilution
What is formed from an acid and a METAL reacting
A salt + hydrogen
What is formed from an acid and a metal CARBONATE reacting
A salt + water + carbon dioxide
What is formed from acid reacting with a metal OXIDE
A salt + water
What is formed from acid reacting with a metal HYDROXIDE
Salt + water
How do you name the salt that is formed
1: take the name of the metal
2: identify the type of acid and it’s salt ending
3: combine them
E.g. copper + sulphuric acid —> copper sulphate
What is a spectator ion
One which is unchanged (does not change state) on both sides of the reaction.
What is a titration
An experiment in which the exact volume of reactants is measured to find the volume, number of moles, mass, gfm or concentration.
What is a homologous series
A group of hydrocarbons with similar chemical properties that share the same general formula
What is a hydrocarbon
A compound containing the elements hydrogen and carbon
What is the general formula of an alkane
CnH2n+2
How do you name an alkane
1: find the length if the longest row of carbon backbone atoms within the molecule and use its prefix
2: indicate the position of the branch using numbers, based on which carbon backbone atom the branch is on
3: indicate the quality of the branch depending on how long it is
H H H H
E.g. I I I I
H-C-C-C-C-H 2 - methylbutane
I I I I
H ch3 H H
What are the prefixes used to indicate the number of branches
Di, tri, tetra…
What are the prefixes used to indicate how many carbon atoms are on the branch
Methyl (one Carbon), ethyl (two carbons)
What are the prefixes used to indicate the longest chain of carbon atoms
Meth- (1), eth- (2), pro- (3), but- (4), pent- (5), hex- (6), hept- (7), oct- (8)
What happens to the solubility and miscibility of hydrocarbons as the number of carbon atoms increases
The solubility and miscibility decrease (up to around butane they hydrocarbons are soluble and miscible, the larger ones are not)
What do all alkanes end with
-ane
What is the general formula of the alkene series
CnH2n
What do all alkenes end with
-ene